As a refresher course on our seasonal occurrence of low dissolved oxygen on Lake Taneycomo, I wanted to reiterate some facts about how this affects our trout, and how to lessen the potential damage to our trout fishery.
The Missouri Clean Water Act states that the minimum dissolved oxygen level required is 6 p.p.m while the federal act requires only 4 p.p.m.. The Corps, as a federal agency, abides by its own rules even though in the state of Missouri. That's means the Corps only has to keep the D.O. levels in the water entering Lake Taneycomo above 4 p.p.m., which really is the minimum quality to keep fish lively and productive.
Fishing-wise, when our D.O. levels are at 4 p.p.m., we notice that the trout we hook and fight are sometimes sluggish and don't fight very hard. They also have a hard time "catching their breath" after a fight. This is why, if it's your intent to release your catch, the way you handle caught fish will dictate whether your fish will survive after release.
Here are some things to think about when handling big trout:
- Get the fish in the net as quickly as possible. Long, drawn-out fights will kill a big trout, just like other species of fish like stripers.
- After netting the fish, keep it in the water. Remove the hook while it is still in the water and only lift the fish out of the water to take a pic. You can even measure it in the water if you have a cloth tape but if you do not, keep the fish in the net while measuring it if possible.
- Hold the fish in the net underwater and work with it if necessary, moving it back and forth to force water through its gills. Make sure it is strong enough to at least swim out of the net before releasing. If a fish is released and it falls to the bottom on its side, silt will cover its gills and it will die.
- When taking a photo try to hold the fish over a net at all times, so if the fish drops, it won't hit the boat's hard surface. If it's a bigger trout, hold it horizontal, not vertical. There have been studies on bass that show holding a big bass vertically puts undue pressure on its organs and can cause damage. I have, to this point, not found any studies on trout.
- Bogas and Fish Grips - Used on smaller trout (<18 inches) are probably okay if applied correctly to the fish's jaw, but using a grip on a trophy trout may cause serious damage to it. The clip should be applied to the lower jaw inside the mouth and NOT back by the gills. If a fish flops while the clip is applied through the gill plate, the clip will hit the gills and cause damage and bleeding. I've seen many pictures of trout on Facebook with the clips through the gills and blood running down the sides of the fish. That fish is dead. If it's being kept, that's fine. If a big trout is clipped in the lower jaw and it bolts, the action of the heavy fish will cause the clip to cut all the way through the outer jaw. This will impede the fish's ability to eat and eventually the fish will die a slow death. I've broken the lower jaw of two big rainbows while fishing in Alaska using a boga. . . believe me, it's not an experience you want to have.
- Keep in mind, a fish's gills are exposed to air when held out of the water. During extreme hot and cold weather, the air can cause damage to the gills in a very short period of time, even seconds. In the case of extreme cold weather, the gills could actually flash freeze, killing the fish immediately. I've seen it happen unfortunately.
This fall, with our brown trout starting to move up lake already, we're expecting a banner year of catching trophy browns and rainbows. If we want to see this continue, we need to take care of these fish.